Britain’s decision to expand its nuclear arsenal may also cause tensions. In its last defense review in 2015, the government disclosed the numbers of missiles and warheads that it planned to carry on submarines. In this review, Britain said it would no longer give numbers for its operational stockpile.

“The decision to reduce the level of transparency on the U.K. nuclear stockpile will not go down well with U.S. officials who want to signal an openness to more progress on nuclear disarmament,” said Malcolm Chalmers, the deputy director general of the Royal United Services Institute, a think tank in London. “The U.K. decision on this would have been easier to sell to the Trump administration.”

View Source